The present invention is directed to data processing systems and more particularly to a diagnostic method and circuit for evaluating fault conditions in bus voltages within a data processing system.
Data processing systems provide a diagnostic routine for detecting various fault conditions in operating parameters of the system. One type of parameter which is especially important to the operation of the system is the bus voltages appearing on the input connection to various printed circuit boards on which are located the processing elements that comprise the data processing system. In monitoring such bus voltages, a zero voltage reading may indicate an actual zero bus voltage or the presence of an open condition in the circuit. Presently available measuring devices such as voltmeters and ohmeters cannot accurately predict the cause of such voltage readings by themselves without the addition of a plurality of measuring devices acting together which would require the addition of a plurality of sensing lines to the system.
It is therefore a principal object of this invention to provide a method and circuit for automatically determining the status of an input connection.
It is a further object of this invention to provide a method and circuit for automatically detecting a fault condition in a data processing system which pertains to voltages on a voltage distribution bus.
It is another object of this invention to provide a method and circuit for automatically determining a fault condition without requiring the addition of a plurality of diagnostic sensing lines in the system.